1. Technical Field
The present invention relates to an image processing apparatus, an image processing method, an image capturing apparatus, and a computer readable medium storing thereon a program. In particular, the present invention relates to an image processing apparatus and an image processing method for processing a captured image, an image capturing apparatus for capturing an image, and a computer readable medium storing thereon a program used by the image processing apparatus and the image capturing apparatus.
2. Related Art
A camera provided with an objective lens having a PSF two times greater than the pitch of the light receiving element array is known as in, for example, Japanese Unexamined Patent Application Publication No. 2006-519527. Furthermore, a technique for causing an optical transfer constant of optical imaging to be substantially constant in relation to the aberrations concerning the focal point by using optical elements that change a phase of a wave surface is known as in, for example, Japanese Unexamined Patent Application Publication No. 2006-523330.
It is easy for the PSF shape of the light from an object to change if the object is on an axis or removed from an axis. Accordingly, when the processes disclosed in the above patent documents are employed to restore an entire image region using the same filter, an artifact may arise depending on the region. Furthermore, the restoration may be performed using a filter with different restoration characteristics for different image regions, but switching the filter for each region increases the computation time of the restoration process.